The mosquito that bites you is a female member of the family Culicidae of which there are many subspecies.

Mosquito bites cause a systemic allergic reaction in most people followed by a pruritic wheal (a reddish bump the size of a finger nail) that itches. Scratching this wheal often results in a local infection, although in some people infection follows even if they do not scratch.

Mosquitoes mostly feed off the nectar of plants and it is only the female that needs mammal blood, often only required before laying its raft of eggs.

Mosquitoes find their mammal hosts in many ways. They are attracted by estrogens, sweat, exhaled breath, moisture and warmth.

Initially it was thought that mosquitoes only carried malaria but now we know that they are the carriers of many other diseases like dengue fever, Ross River disease and West Nile virus.

When a mosquito bites it injects an anti-coagulant to ease the blood flow as well as some of the saliva of the insect.

Reaction to mosquito bites varies considerably amongst humans. Initially, in small children it takes around 24 hours for a wheal or bump to develop.

There is normally no reaction to the very first bite but it does provoke a reaction. Antibodies are created and the more bites you receive the more antibodies are produced. Now your immune system is active and every subsequent bite becomes inflamed and itchy, not because of the bite, but because of your body's reaction. Eventually the immune system is so sensitive and so reactive that an itchy weal can develop within minutes of being bitten.

Many people have extreme reactions because their immune system has become hypersensitive to the bites and abnormally big wheals (that itch like crazy) can develop.

A minority of people become desensitized to mosquito bites. Some even believe that mosquitoes do not bite them but that is not the case. It is true that some of us attract more mosquitoes than others but we all get bitten over time and the fact that some have no immune response does not mean that they are not exposed to the diseases carried by mosquitoes.

There are many substances that ease the effect of mosquito bites - see below.

Prevention is better than cure but this is not easy as it takes only a short lapse in your defense for a mosquito to find you. There are several substances that you can use topically to avoid the bites but these only help when they are applied everywhere.

Neck to toe clothing helps some but, seeing that mosquitoes are only a problem in warmer areas and summers, if it means that you become hot as a consequence, you will attract more mosquitoes albeit offering them a smaller area to work with.

Garlic has been known to be effective if ingested as a repellent. The odor makes you less attractive to mosquitoes, but as odor free garlic preparations will not work you may also repel your friends.